As a motorcyclist, visibility is paramount to the safety of the rider. With this in mind, Pete Mills wired up his own super-bright brake light assembly using bright red LEDs. Not only are the lights powered by the onboard electrical system, but they can be toggled to either stay solid, or blink depending on the rider’s choice. This was done using an ATTiny85 microcontroller.

In addition to being an online editor for MAKE Magazine, Michael Colombo works in fabrication, electronics, sound design, music production and performance (Yes. All that.) In the past he has also been a childrens’ educator and entertainer, and holds a Masters degree from NYU’s Interactive Telecommunications Program.

Note that blinking brake lights are illegal in quite a few states (and can produce a rather incredible sized traffic citation). The reason is that a blinking brake light looks kind of like an emergency vehicle, at least from a distance, and the various states don’t want any confusion.

Also, there may be regulations dealing with various aspects of vehicle lighting, such as colour, direction, intensity, reliability, etc. And/or, some states may require “type approved” lights. Thus, it would be good for anyone contemplating such a project to check their various laws, plus those of the federal government, too.

But, yeah, I’m a motorcyclist, too, and anything that will help is a good thing!

Dave

John

FYI – This is legal in VA. Although there is max time limit that the blinking can occur. 5 seconds i think.

http://www.facebook.com/michaelcolombo Michael Colombo

Thanks for the info Dave. In fact, Pete does address the legal issues in his blog post, which I’m pasting below:

“I’m not too sure what to say about the legality of this project. I read the entire vehicle code for my state. There was no reference to brake light flashers for cars or motorcycles. The vehicle code for Michigan does prohibit ” rotating, oscillating or flashing lights ” on non-emergency vehicles, however I believe my brake light does not qualify as the clear intent in the vehicle code was ” rotating, oscillating or flashing ” lights that continue to do so for an extended period of time as emergency or police vehicles do. Really, my device is no different than tapping your brake pedal several times before stopping your motorcycle. In the end, I did send an email to the state of Michigan requesting clarification. At the time of this writing there has been no response. I think the bottom line is, don’t modify your vehicle unless you are willing to accept full responsibility for any outcome.”

ambiguator

Make these work with my bicycle brakes, and you can have all my money.

thebes42

You would just need a brake switch and a battery. My little vintage honda just has a momentary switch near the hinge, its a pushbutton on the lever stop which physcially opens when the lever is squeezed and the brake circuit closes. I bet you could probably mount some old motorbike or moped brake levers to pedal push bike bars. Or you could machine a similar inlet into an existing lever mount’s stop and use a weatherproofed switch between the light and ground.

hexmonkey

If the intended end result is increased safety, then doing an accurate measurement of the light intensity output is probably important. There are very specific *Federal* guidelines for this. “Eyeballing it” is not enough.

in lots of places you can measure all you want, only type aproval counts everything else is illegal, so diy is basically out of the question

hexmonkey

Notice I said nothing about legality, I was simply referring to safety. Follow the guidelines that the OEMs have to follow and at least you’ll be on the same level ( assuming nothing about quality control, etc., of course.).

Evros

Why can’t this be implemented using a 555 and a nice analog circuit. Isn’t the microcontroller an overkill ? I keep bumping on some simple stuff that employ a mCPU while they could have been done with very few components. I guess no one wants to play it smart when they can play it easy with a few C commands and a programmer.

Nice job though. Keep on.

Evros

http://pushtheotherbutton.wordpress.com Michael Colombo

It sure could be done with a 555, but I have the suspicion that Pete used what he was comfortable with. There are tons of makers out there making electronics projects who don’t know moderate to advanced analog electronics, so they stick to microcontrollers.

John

As an inexperienced DIYer I see this type of comment all the time. If you know how it could be done with a 555 please provide some basic info so I (we) can learn.

Evros

Hello John,

I do not have a schematic nor can I sit down and draw an exact circuit that functions in a way similar or better than the one presented above in the next 5 minutes. WIsh I could. With my expertise I believe it would not take more than an afternoon though.

I have seen however more complicated circuits with 555, including blinkers of all sorts or similar, and they were not difficult to understand or built. Plenty of examples on the internet along with explanations. All you need is a proper piece of software or a breadboard and a couple of cheap 555’s.

What I am saying is that sometimes it is a lot easier to achieve the same functionality with analog circuitry avoiding the “fuss” of playing with mcu’s, writing the software, programming etc. Whell it is not much of fuss really but you get the point. It is a steeper learning curve but it is worth it.

Moreover you are using a complete mcu, a system on a chip, capable of achieving amazing things just to blink a few led’s. Isn’t that something like using a tank to go to the grocery store to pick up some apples ?

Honestly Pete has done a nice job. Bravo. All I am saying is that trouble is sometimes worth it.

John

I understand what you are saying, it is just that in my case I am coming from a software background. Naturally that leads me to look towards software solutions. I did a cursory search for a multi state 555 LED setup, but I dont know exactly what the search terms should be.

Daedalus62

Nice project… I’m a motorcyclist also, and I think this is an excellent add-on to any motorcycle, especially if (like me) most of your ride is in the city traffic.